Hi,

This really is a question for the United section of FT, as the problem is getting them out of United, rather than into BAEC.

The currency of BA executive club is Avios points. This is the same currency used by three different schemes:
- BA Executive Club (worldwide, essentially)
- Iberia Plus (worldwide)
- Avios.com (UK only)

All three of these separate schemes use Avios points, and you can move Avios points between your accounts in each of them (subject to a couple of rules).

As a result, you are looking for a route from United to either BAEC or IB+.
(Avios.com is too new, and under connected to other schemes).

BAEC accepts credits from hotels schemes, Amex membership rewards points, etc.

But the key question, is what does United let you convert out into (if anything!). That is a question for the United forum.

Note: None of the three Avios points using schemes, BAEC/IB+/Avios.com have exit routes to other loyalty currencies. Only between schemes using Avios.