With given information, question can be looked though below angels :-

1. As tenure goes up Libor rates also goes up. As of today 3 Month USD Libor: 0.63060, 6 Month Libor: 0.89720 and 12 Month Libor: 1.21160. An importer would prefer using lower tenure Libor rates.
2. Overseas Bank would prefer to link Libor tenure with respective transaction tenure. Say if buyers credit is taken for 180 days then 6 Month Libor is applicable and if buyers credit is taken for 1 year then 12 Month Libor. This allows bank to link funds with respective tenure of loans and thus reduce interest rate risk .
3. There are few banks which give an option to link buyers credit transaction with different tenure Libor rates in case of large value deals. For example, if the importer is taking Buyers Credit for 1 year tenure but pricing is linked to 6 Month Libor reset. Importer has to two aspects in such scenario:
   • If Libor goes up after six month his costing will go up and same is true other way round.
   • Every 6 Month importer will have to make payment of interest, where as  if the transaction was taken with 12 Month Libor, he would have to make payment of interest only after 12 Months.
4. Last Aspect is on regulation perspective:
   • Buyers Credit Upto 3 Years: Buyers credit can be taken for any tenure linked with any Libor tenure till the time it remains within maximum cap of 6 Month Libor + 350 bps.
   • Buyers Credit Upto 5 Years: Minimum tenure for buyers credit has to be 6 Month or above from the beginning. But here also there is no restriction on Libor. Thus for a 6 month tenure if a bank is ready to provide buyers credit with 3 Month Libor Reset, the same can be taken. Again here also interest rates should remain within the cap of 6 Month Libor + 350 bps.

Reference Article.

1. Buyers Credit
2. Libor Rates