While Harvard students have been involved with divestiture from South Africa in recent weeks by April 20 they will have so deal with a divestiture clear to home that of American Telephone and Telegraph from its regional divisions.

As a result of the Justice Department's successful breakup of the telecommunications titan in 1984, consumers now have more choices available for-and more decisions to make about what long-distance company they want.

At Harvard, students will have to pick from among nine different companies which hope to lure customers away from AT&T Customers can choose a company as

How much does it cost to make a 10-minute phone call from Cambridge to New York City at 6 p.m., a weeknight? Allnet: 42.30  MCI: $2.21 AT&T: $2.62  SBS skyline: $ 2.70 First Phone Link Service: $1.64 GIE Sprint: $2.08  ITT: $1.96 US Telecommunications: $2.75

How much does it cost to make a 10-minute call from Cambridge to Los Angeles at 5 p.m. Saturday? Allnet: $1.86  MCI: $1.76 AT&T: $1.96  SBS Skyline: $1.70 First Phone Link Service: $1.64 GTE Sprint: $1.67  ITT: $1.67 US Telecommunications: $3.14