http://www2.ed.gov/policy/rights/reg/oc ... 106.html#D
§ 106.37 Financial assistance.
(a) General. Except as provided in paragraphs (b) and (c) of this section, in providing financial assistance to any of its students, a recipient shall not:
(1) On the basis of sex, provide different amount or types of such assistance, limit eligibility for such assistance which is of any particular type or source, apply different criteria, or otherwise discriminate;
(2) Through solicitation, listing, approval, provision of facilities or other services, assist any foundation, trust, agency, organization, or person which provides assistance to any of such recipient's students in a manner which discriminates on the basis of sex; or
(3) Apply any rule or assist in application of any rule concerning eligibility for such assistance which treats persons of one sex differently from persons of the other sex with regard to marital or parental status.
(b) Financial aid established by certain legal instruments. (1) A recipient may administer or assist in the administration of scholarships, fellowships, or other forms of financial assistance established pursuant to domestic or foreign wills, trusts, bequests, or similar legal instruments or by acts of a foreign government which requires that awards be made to members of a particular sex specified therein; Provided, That the overall effect of the award of such sex-restricted scholarships, fellowships, and other forms of financial assistance does not discriminate on the basis of sex.
(2) To ensure nondiscriminatory awards of assistance as required in paragraph (b)(1) of this section, recipients shall develop and use procedures under which:
(i) Students are selected for award of financial assistance on the basis of nondiscriminatory criteria and not on the basis of availability of funds restricted to members of a particular sex;
(ii) An appropriate sex-restricted scholarship, fellowship, or other form of financial assistance is allocated to each student selected under paragraph (b)(2)(i) of this section; and
(iii) No student is denied the award for which he or she was selected under paragraph (b)(2)(i) of this section because of the absence of a scholarship, fellowship, or other form of financial assistance designated for a member of that student's sex.
(c) Athletic scholarships. (1) To the extent that a recipient awards athletic scholarships or grants-in-aid, it must provide reasonable opportunities for such awards for members of each sex in proportion to the number of students of each sex participating in interscholastic or intercollegiate athletics.
(2) Separate athletic scholarships or grants-in-aid for members of each sex may be provided as part of separate athletic teams for members of each sex to the extent consistent with this paragraph and §106.41.
§ 106.41 Athletics.
(a) General. No person shall, on the basis of sex, be excluded from participation in, be denied the benefits of, be treated differently from another person or otherwise be discriminated against in any interscholastic, intercollegiate, club or intramural athletics offered by a recipient, and no recipient shall provide any such athletics separately on such basis.
(b) Separate teams. Notwithstanding the requirements of paragraph (a) of this section, a recipient may operate or sponsor separate teams for members of each sex where selection for such teams is based upon competitive skill or the activity involved is a contact sport. However, where a recipient operates or sponsors a team in a particular sport for members of one sex but operates or sponsors no such team for members of the other sex, and athletic opportunities for members of that sex have previously been limited, members of the excluded sex must be allowed to try-out for the team offered unless the sport involved is a contact sport. For the purposes of this part, contact sports include boxing, wrestling, rugby, ice hockey, football, basketball and other sports the purpose or major activity of which involves bodily contact.
(c) Equal opportunity. A recipient which operates or sponsors interscholastic, intercollegiate, club or intramural athletics shall provide equal athletic opportunity for members of both sexes. In determining whether equal opportunities are available the Director will consider, among other factors:
(1) Whether the selection of sports and levels of competition effectively accommodate the interests and abilities of members of both sexes;
(2) The provision of equipment and supplies;
(3) Scheduling of games and practice time;
(4) Travel and per diem allowance;
(5) Opportunity to receive coaching and academic tutoring;
(6) Assignment and compensation of coaches and tutors;
(7) Provision of locker rooms, practice and competitive facilities;
(8) Provision of medical and training facilities and services;
(9) Provision of housing and dining facilities and services;
(10) Publicity.
Unequal aggregate expenditures for members of each sex or unequal expenditures for male and female teams if a recipient operates or sponsors separate teams will not constitute noncompliance with this section, but the Assistant Secretary may consider the failure to provide necessary funds for teams for one sex in assessing equality of opportunity for members of each sex.
(d) Adjustment period. A recipient which operates or sponsors interscholastic, intercollegiate, club or intramural athletics at the elementary school level shall comply fully with this section as expeditiously as possible but in no event later than one year from the effective date of this regulation. A recipient which operates or sponsors interscholastic, intercollegiate, club or intramural athletics at the secondary or post-secondary school level shall comply fully with this section as expeditiously as possible but in no event later than three years from the effective date of this regulation.
It's not clear to me whether a stipend would be considered an "athletic scholarship" under paragraph (c) of subsection 106.37. If so, they must be offered to women "in proportion" to the number of student athletes of each sex. So if there are 150 male student athletes, and 85 are given stipends, that's 57%. If there are 140 women student athletes, you will need only 79. The number of student athletes of each sex are typically close, to satisfy the "equal opportunity" required in subsection 106.41, but if they are different, yes there could be a slight difference in aid requirements. If the stipend is not considered a scholarship, it may fall under paragraph (a), which prohibits offering different amounts of financial assistance on the basis of sex.
Not giving women student athletes equal stipends could also violate paragraph (c) in §106.41 that mentions per diem allowances as a factor used in assessing "equal opportunity."