ASHGABAT, Oct 4 - Turkmenistan signed a deal Wednesday to sell $1.39 billion worth of natural gas to Ukraine, Turkmen President Saparmurat Niyazov said.

Under the deal, Ukraine will buy a total of 35 billion cubic meters (1.2 trillion cubic feet) of gas from Turkmenistan over the next 15 months.

The price will be $38 per 1,000 cubic meters (35,000 cubic feet) this year and $40 next year, with Ukraine paying the costs of transporting the gas from the Turkmen border through Uzbekistan to its own consumers.

Ukraine will pay for the gas with 40 percent in cash and 60 percent "investment and goods" until the end of 2000. The two forms of payment will be made in equal amounts next year.

The deal, signed between Niyazov and Ukraine President Leonid Kuchma, requires Ukraine to make weekly advance payments of $7 million in cash and $9 million in goods to ensure payments are made regularly.

Ukraine, which is one of the world's biggest natural gas consumers, depends on supplies from neighboring Russia and is seeking ways to find gas at lower prices. Kuchma rejected an earlier proposed deal with Turkmenistan for gas at $42 per 1,000 cubic meters, saying transport costs made it a bad arrangement for Ukraine.