New York University’s 2,400 adjunct faculty members will receive substantial pay increases and benefits for the summer hours they work under the terms of a new contract with the private institution. The agreement, ratified last week, is the product of tough negotiations that had left adjunct faculty members poised to go on strike. In an attempt to deal with the earnings gap between adjunct faculty members who teach credit-bearing courses and the lesser-paid adjunct faculty members who teach noncredit courses, the contract calls for all adjunct faculty members’ pay to rise by the same dollar amount, so that the latter group will see its pay climb at a steeper rate. (The $4-per-contact-hour increase in the contract’s first year amounts to about a 3.6 percent raise for those who teach credit-bearing courses and a 6.7 percent increase for those who teach noncredit courses.) The agreement also builds on gains won by adjunct faculty members in their 2004 contract by, for the first time, offering health insurance, job security, and retirement benefits to those who work in the summer.